The game is fun and addictive. But levels are timed, i.e. you have to survive x minutes without mishaps, before advancing to the next level. Would be better is you had to land/takeoff x planes before advancing. Why? Because now it happens I have 3 or more planes taxi-ing to the gate and if the time runs out, no points! Feels unfair after going through all the trouble to land them safely.
Furthermore, my ingame purchase of extra levels didn't work. The order was placed and payed, but the game keeps ending after finishing level 2.